It's a well known phenomenon, your taste buds work differently depending on temperature
(Old article, advanced copy paste protection, won't let me copy pieces of text)
In a nutshell, warmer food enhances taste. For some products cold is better, drinking melted ice cream is too sweet (yet too cold and you don't taste it) warm beer/wine too bitter. Yet coffee and tea depend on their bitter taste and taste better hot. Cold coffee loses its flavor.